"Fingers crossed of course, I don't foresee any baby-related interruptions or delays," she said. "Let me reassure you that book six remains well on track."

The author, who has sold over 260 million Potter books worldwide, said she always wanted three children. "I could not be happier," she added.

Of the recently announced sixth book, Harry Potter and the Half Blood Prince:

Now, I know that many Harry Potter fans first reaction will be what does this mean for the timing of book six? (I'm not maligning you… I'm sure you're happy for me... but I know you really want that book!) So let me reassure you that book six remains well on track.

I still can't say for sure when it will be finished, but I have written a lot and I really like it (a reckless challenge to fate, that; I bet the next chapter goes horribly wrong now).